The caution flags, plus the fact that someone knew to be shooting this leads me to believe that this was at least partially intentional. Neither of those things would be if this were an ordinary day-to-day operation gone south. It doesn’t seem like the fire was unexpected, either, although people are definitely running for cover just before the chain plays out.

Minor note: The crossbar on the links of anchor chain are there to make it heavier rather than stronger. You want the bottom of the chain heavier than the rest of it so that it comes away from the anchor relatively horizontal, but the higher sections lighter and more vertical so that the circle that the ship swings around as the current changes is smaller.